Walter Roberson

Last seen: Today | Active since 2011

I do not do free private consulting. If you want to bring my attention to something, send a link to the MATLAB Answers location. I am currently caught up to T0099119; if you are waiting on a reply from me for an older issue, please send me a reminder.

Programming Languages:
C, MATLAB, Shell, Perl, Fortran
Spoken Languages:
English

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Answered
How do I map grayscale values to get temperature?
"I want to know if i can use these GL values to get corresponding temperature with any equation or any function." No, there i...

11 hours ago | 0

Answered
How can we convert a number into a string value with the exact number of digits present in the number?
The digits "actually present" in the number assigned are 0.0199154999999999991755483819133587530814111232757568359375 The n...

11 hours ago | 0

Answered
An error "Assumed incident matrix must contained negative value for link out." which occurs in creating a graph object.
You are using https://www.mathworks.com/matlabcentral/fileexchange/12648-graph-package That code does not support passing in ...

16 hours ago | 0

Answered
i can't figure out what to do , and it's urgent , need your help please !
https://github.com/petercorke/robotics-toolbox-matlab

20 hours ago | 0

Answered
round to 2 decimal places but still have more than 2 decimal places when storing
2 and 100 are relatively prime, so it is not possible for any finite base 2 fractional representation to *exactly* represent 1/1...

23 hours ago | 1

Answered
plot textdata with NaN
T = readtable('https://www.mathworks.com/matlabcentral/answers/uploaded_files/1002155/owid-covid-data_2020-21.csv', 'VariableNam...

1 day ago | 0

Answered
how to extract the watermark after decryption. please help I am getting an error in watermark extraction steps. Thank you in advance
for i=1:1:70000 x(i+1)=l*x(i)*(1-x(i))+b*y(i)*y(i)*x(i)+a*z(i)*z(i)*z(i); y(i+1)=l*y(i)*(1-y(i))+b*z(i)*z(i)*y(i)+a...

1 day ago | 0

Answered
Iterative solution to approach desired value
fzero() or fsolve(). If you need to be able to look at the complete source code then https://www.mathworks.com/matlabcentral...

1 day ago | 0

Answered
Matlab gives back ''symsum'' formula but not a value
Wolframalpha calculates the first sum numerically, not able to find a closed form for it. What reason do you have to expect t...

1 day ago | 0

Answered
Baseline Criteria: How to read discrete data from excel rather than continuous data.
https://www.mathworks.com/help/simulink/slref/fromspreadsheet.html configure Interpolation to "zero order hold"

2 days ago | 0

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Image file saving location
outdir = 'C:\Users\leehj\Desktop\aaa'; for i = 1:5 h = imagesc(X, Y, Z(:,:,i)); xlim([-2 2]); ylim([-1 1]); fname ...

2 days ago | 0

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Answered
Can I use the Guide function of MATLAB to create GUI in Raspberry Pi?
No, not a chance. What is supported for the Raspberry Pi is to use Simulink to send images (possibly computed) to the Raspberry...

2 days ago | 0

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Answered
So i have a vector of [1x2e6] of frequency data , so I would like to create a loop so that it stores 10 0.1ms (millisecond) this frequency data and fprint it.
Number_per_group = 10; in_groups = buffer(YourSignal, Number_per_group); fmt = [repmat('%8.5f ', 1, Number_per_group - 1), '...

2 days ago | 0

Answered
Since when has it been possible to dot-index the output of a class method?
Since R2019b. https://www.mathworks.com/help/matlab/release-notes.html?category=language-programming&rntext=&startrelease=R2019...

2 days ago | 2

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Answered
cant read the serial port!!!
https://www.mathworks.com/help/matlab/ref/serialport.html feof() is not defined for serialport objects. It was defined for se...

2 days ago | 0

Answered
I want to design a divider using cordic function, for high number / low number (30/2) can anyone help me.?
Do not start with i=1. Start with i being the negative of the number of bits before the decimal place. I believe that your el...

3 days ago | 0

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Answered
magnetic resonance spectroscopy imaging
* use a higher quality device with a stronger magnetic field * have the device calibrated by experts * make sure that the room...

3 days ago | 0

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Answered
plot textdata with NaN
Give up on reading the file that way. Use readable() instead.

3 days ago | 0

Answered
How can I solve this error about nargout function?
(That looks like GUIDE code) You are trying to do code generation with variable numbers of output. MATLAB Coder is not able t...

3 days ago | 0

Answered
How to plot 2D location vs corresponding data in MATLAB
You can create a triangulation object and then use trimesh() to plot the data. Or you can create a scatteredInterpolant() obj...

3 days ago | 0

Answered
Simulink fixed-step size protected variable name
"Is there any protected variable name for the Fixed-step size solver property pane that can be used in a block?" No, there is...

3 days ago | 0

Answered
Why do I receive an error message "archive is not a ZIP archive" during MATLAB installation on Linux?
In current MATLAB versions, a downloader is used that downloads archives as required; when using the downloader, the error just ...

3 days ago | 0

Answered
Error installing R2016b: archive is not a ZIP archive
In current MATLAB versions, a downloader is used that downloads archives as required; when using the downloader, the error just ...

3 days ago | 0

Answered
How can I plot the population before evaluating fitness in Matlab GA?
You cannot do that using ga() . ga() will never pass the state to the fitness function. You are also assuming that ga() is cr...

3 days ago | 0

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Answered
Now my question what should I add in that code to make the code display 0 on the values less than 0 because now with my code it goes down to the negative values.Thank you.
You should be multiplying logical conditions, not adding them.

3 days ago | 0

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Answered
Matlab keeps shutting down while my program is running
One thing I would check is for overheating <https://www.bestmaccleaner.com/mac-temperature-monitor/> I also suggest testing...

3 days ago | 0

Answered
Error in appliying split apply
Sometimes the cause of this is having used a function such as max() that operates along the first non-scalar dimension, together...

3 days ago | 0

Answered
How do I manipulate a large row and column datafile and convert each of many bytes to decimal from HEX
Use readlines(), which will return back a string array, one entry per line. Extract the appropriate indices. arrayfun() a ssca...

3 days ago | 0

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Answered
elemental wise function of any kind not functioning
Give the command format long g and try again. You have format short in effect by default. format does not change the ans...

4 days ago | 1

Answered
How to get MATLAB to process the files specified in batch
You can have the code call uigetdir() if you want to prompt the user for the directory name. Or you can make the main functio...

4 days ago | 0